Method and system for forming patterns using charged particle beam lithography with variable pattern dosage

Abstract

A method and system for fracturing or mask data preparation or optical proximity correction or proximity effect correction or mask process correction is disclosed in which a set of shaped beam shots is determined that is capable of forming a pattern on a surface, where the set of shots provides different dosages to different parts of the pattern, and where the dose margin from the set of shots is calculated. A method for forming patterns on a surface is also disclosed.

1 .- 25 . (canceled) 
     
     
         26 . A method for fracturing or mask data preparation or proximity effect correction or optical proximity correction or mask process correction, the method comprising:
 determining a plurality of shaped beam charged particle beam shots (“shaped beam shots”) for an exposure pass, wherein the plurality of shaped beam shots is capable of forming a pattern on a surface, wherein at least two shots in the plurality of shaped beam shots are designed to overlap in the exposure pass, wherein the step of determining comprises calculating a dose margin from the plurality of shaped beam shots, and wherein the step of determining is performed using one or more computing hardware processors.   
     
     
         27 . The method of  claim 26  wherein the dose margin is optimized. 
     
     
         28 . The method of  claim 27  wherein the plurality of shaped beam shots produces a higher dosage peak near a perimeter of the pattern on the surface than in an interior area of the pattern on the surface. 
     
     
         29 . The method of  claim 26  wherein the calculating comprises charged particle beam simulation. 
     
     
         30 . The method of  claim 29  wherein the charged particle beam simulation includes at least one of a group consisting of forward scattering, backward scattering, resist diffusion, Coulomb effect, etching, fogging, loading and resist charging. 
     
     
         31 . The method of  claim 26 , further comprising:
 revising the plurality of shaped beam shots; and   recalculating the dose margin if the dose margin is lower than a pre-determined target dose margin.   
     
     
         32 . The method of  claim 26  wherein each shot in the plurality of shaped beam shots comprises an assigned dosage, and wherein the assigned dosages of at least two shots in the plurality of shaped beam shots differ from each other before dosage correction for long-range effects. 
     
     
         33 . The method of  claim 26  wherein each shot in the plurality of shaped beam shots is a variable shaped beam (VSB) shot. 
     
     
         34 . The method of  claim 26  wherein the surface comprises a reticle to be used in an optical lithographic process to manufacture a substrate. 
     
     
         35 . A method for fracturing or mask data preparation or proximity effect correction or optical proximity correction or mask process correction, the method comprising:
 determining a plurality of shaped beam charged particle beam shots (“shaped beam shots”) for an exposure pass, wherein a shape of a first charged particle beam for a first shot in the plurality of shaped beam shots overlaps a shape of a second charged particle beam for a second shot in the plurality of shaped beam shots, wherein the plurality of shaped beam shots is capable of forming a pattern on a surface, wherein the step of determining comprises calculating a dose margin from the plurality of shaped beam shots, and wherein the step of determining is performed using one or more computing hardware processors.   
     
     
         36 . The method of  claim 35  wherein the dose margin is optimized. 
     
     
         37 . The method of  claim 36  wherein the plurality of shaped beam shots produces a higher dosage peak near a perimeter of the pattern on the surface than in an interior area of the pattern on the surface. 
     
     
         38 . The method of  claim 35  wherein the calculating comprises charged particle beam simulation. 
     
     
         39 . The method of  claim 38  wherein the charged particle beam simulation includes at least one of a group consisting of forward scattering, backward scattering, resist diffusion, Coulomb effect, etching, fogging, loading and resist charging. 
     
     
         40 . The method of  claim 35 , further comprising:
 revising the plurality of shaped beam shots; and   recalculating the dose margin if the dose margin is lower than a pre-determined target dose margin.   
     
     
         41 . The method of  claim 35  wherein each shot in the plurality of shaped beam shots comprises an assigned dosage, and wherein the assigned dosages of at least two shots in the plurality of shaped beam shots differ from each other before dosage correction for long-range effects. 
     
     
         42 . The method of  claim 35  wherein each shot in the plurality of shaped beam shots is a variable shaped beam (VSB) shot. 
     
     
         43 . The method of  claim 35  wherein the surface comprises a reticle to be used in an optical lithographic process to manufacture a substrate.